diff --git a/core/agents/agents.go b/core/agents/agents.go
index f31fbd94..23068844 100644
--- a/core/agents/agents.go
+++ b/core/agents/agents.go
@@ -5,10 +5,10 @@ import (
 	"strings"
 	"time"
 
-	"github.com/navidrome/navidrome/model"
-
 	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/consts"
 	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/model"
 	"github.com/navidrome/navidrome/utils"
 )
 
@@ -42,6 +42,9 @@ func (a *Agents) AgentName() string {
 }
 
 func (a *Agents) GetArtistMBID(ctx context.Context, id string, name string) (string, error) {
+	if id == consts.UnknownArtistID {
+		return "", ErrNotFound
+	}
 	start := time.Now()
 	for _, ag := range a.agents {
 		if utils.IsCtxDone(ctx) {
@@ -61,6 +64,9 @@ func (a *Agents) GetArtistMBID(ctx context.Context, id string, name string) (str
 }
 
 func (a *Agents) GetArtistURL(ctx context.Context, id, name, mbid string) (string, error) {
+	if id == consts.UnknownArtistID {
+		return "", ErrNotFound
+	}
 	start := time.Now()
 	for _, ag := range a.agents {
 		if utils.IsCtxDone(ctx) {
@@ -80,6 +86,9 @@ func (a *Agents) GetArtistURL(ctx context.Context, id, name, mbid string) (strin
 }
 
 func (a *Agents) GetArtistBiography(ctx context.Context, id, name, mbid string) (string, error) {
+	if id == consts.UnknownArtistID {
+		return "", ErrNotFound
+	}
 	start := time.Now()
 	for _, ag := range a.agents {
 		if utils.IsCtxDone(ctx) {
@@ -99,6 +108,9 @@ func (a *Agents) GetArtistBiography(ctx context.Context, id, name, mbid string)
 }
 
 func (a *Agents) GetSimilarArtists(ctx context.Context, id, name, mbid string, limit int) ([]Artist, error) {
+	if id == consts.UnknownArtistID {
+		return nil, ErrNotFound
+	}
 	start := time.Now()
 	for _, ag := range a.agents {
 		if utils.IsCtxDone(ctx) {
@@ -122,6 +134,9 @@ func (a *Agents) GetSimilarArtists(ctx context.Context, id, name, mbid string, l
 }
 
 func (a *Agents) GetArtistImages(ctx context.Context, id, name, mbid string) ([]ExternalImage, error) {
+	if id == consts.UnknownArtistID {
+		return nil, ErrNotFound
+	}
 	start := time.Now()
 	for _, ag := range a.agents {
 		if utils.IsCtxDone(ctx) {
@@ -141,6 +156,9 @@ func (a *Agents) GetArtistImages(ctx context.Context, id, name, mbid string) ([]
 }
 
 func (a *Agents) GetArtistTopSongs(ctx context.Context, id, artistName, mbid string, count int) ([]Song, error) {
+	if id == consts.UnknownArtistID {
+		return nil, ErrNotFound
+	}
 	start := time.Now()
 	for _, ag := range a.agents {
 		if utils.IsCtxDone(ctx) {